Known in the art are liquid crystal 4-(trans-4"-n-alkylcyclohexylmethoxy)-4'-cyanodiphenyls (cf. Mol. Cryst.Liq.Cryst. vol. 53, 1979, Gordon & Breach Science Publishers, Ltd., London, G. W. Gray, D. G. McDonnel "liquid Crystal Compounds Incorporating the Trans-1,4-Substituted Cyclohexene Ring System", p. 155).
These compounds have a disadvantage residing in a high temperature of the formation of a mesomorphic (nematic) phase (not less than 93.degree. C.), a high heat of the transition from the liquid phase into the liquid-crystal one (.DELTA.H not less than 4.8 kcal/mol) which limits their use as components of liquid crystal compositions possessing low temperatures of liquid-crystal phase formation. Thus, a composition consisting of 14% by weight of 4-(trans-4"-n-butylcyclohexylmethoxy)-4'-cyanodiphenyl and 86% by weight of 4-n-pentyl-4'-cyanodiphenyl has a sufficiently high temperature of the liquid-crystal phase formation equal to 11.degree. C. and features a narrow temperature range of the existence of the liquid-crystal phase (47.degree. C.) (see the same publ., p.158).
Another analog of the compounds according to the present invention is exemplified by 4-(4'-cyanodiphenyl) esters of trans-4"-n-alkylcyclohexanecarboxylic acids. The temperature of formation of the liquid-crystal phase of these compounds is not below 79.8.degree. C. (cf. opt, cit.publ., p.153). These compounds feature the same disadvantages as 4-(trans-4"-n-alkylcyclohexylmethoxy)-4'-cyanodiphenyls.